000 FXUS61 KLWX 271355 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 955 AM EDT Mon Jun 27 2022 .SYNOPSIS... A cold front will track through the area today with high pressure expected to settle in for the middle portion of the week. Another cold front is expected to cross the area at the end of the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... The 12Z IAD sounding depicted a very moist environment in place with precipitable waters just short of 2.00 inches. Compared to climatology, these values are running well above the 90th percentile. The current Mid-Atlantic radar mosaic shows a band of frontal showers tracking toward the Shenandoah Valley. 3-hour totals could reach 0.50-1.00" within some of the locally heavier activity. One thing that is lacking at this time is instability with 200-300 J/kg of mixed-layer CAPE, but with notable capping issues. For now, thunder looks unlikely through at least 11 AM, if not longer. The best chance for any thunderstorm activity is south of I-66 and east of U.S. 15. Weak shear profiles will preclude an organized severe threat. However, an isolated severe storm is possible, mainly across southern Maryland. Convective coverage is expected to decrease rapidly after 21Z, but may persist for several more hours into the evening across southern St. Mary's County. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... Clear and cool conditions are expected tonight as high pressure begins to build into the area. Lots of high clouds Tue associated with an upper level jet passing overhead. Pleasant with highs around 80 and very low humidity. Some moisture return is expected Wednesday as winds turn more southerly. Shallow convection is possible across the VA Piedmont according to some of the guidance as a shortwave-trough in NW flow moves across the area. Model soundings show some weak elevated instability, but not enough to produce lightning. Fair weather is expected Wed night behind departing shortwave- trough. && .LONG TERM /THURSDAY THROUGH SUNDAY/... A broad upper level ridge will remain in control across much of the southern half to two-thirds of the country on Thursday and Friday. Dry conditions are expected, but conditions will turn hot. Highs are expected to be around 90 on Thursday, with temperatures soaring well into the 90s on Friday. Dewpoints will be in the upper 50s to near 60 on Thursday, and mid 60s on Friday. By the upcoming weekend, a powerful trough by early July standards will drop down from southern Canada into the Great Lakes. This system will drive a surface cold front southward toward the region, with the airmass out ahead of the front beginning to moisten up. The combination of the front dropping southward and low-levels moistening up will lead to the development of showers and thunderstorms. Some of the storms on Saturday could be on the stronger side. Additional showers and thunderstorms may be possible on Sunday as well, but they would be contingent on the positioning of the front. Some guidance clears the front through the area late Saturday night, while others hang the front up over the area. Temperatures on Saturday should reach well into the 90s once again, while temperatures on Sunday will be dependent on the positioning of the front itself. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... MVFR cigs are possible for a brief period in showers this morning as cold front crosses the area. Afternoon thunderstorms are expected to develop south and east of the main terminals except perhaps at KCHO. Improving weather this afternoon with gradual clearing. No sig wx expected Tue through Wed. VFR conditions are expected on both Thursday and Friday. && .MARINE... Gradient winds are expected to diminish later today as they shift from southerly to WNW as cold front crosses the area. However, a few strong storms are possible this afternoon mainly south of Sandy Point on the Chesapeake Bay and south of Indian Head on the Potomac River which may require Special Marine Warnings. Gradient winds strengthen again after midnight tonight due to a northerly surge behind cold front. Winds diminish Tue afternoon through the middle of the week. Sub-SCA level winds are expected on Thursday. Winds may approach SCA levels in southerly flow Friday afternoon into Friday evening. && .TIDES/COASTAL FLOODING... All coastal flooding issues will drop off after this morning's high tide. Subsequent tidal cycles should see water levels drop off behind the cold frontal passage. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory until 10 AM EDT this morning for ANZ531>533-536-537-539>541. Small Craft Advisory from 11 PM this evening to 10 AM EDT Tuesday for ANZ530>534-537>543. Small Craft Advisory until 2 PM EDT this afternoon for ANZ534- 543. && $$ SYNOPSIS...LFR NEAR TERM...LFR/BRO SHORT TERM...LFR LONG TERM...KJP AVIATION...LFR/KJP MARINE...LFR/KJP TIDES/COASTAL FLOODING...BRO